Ferrite sintered magnet, ferrite particles, bonded magnet, motor, and generator

Abstract

Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R 1-x A x Fe m-y Co y , where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B 2 O 3 . 0.2≤ x ≤0.8  (1) 0.1≤ y ≤0.65  (2) 3≤ m <14  (3)

The invention claimed is: 
     
       1. A ferrite sintered magnet comprising a ferrite phase having a magnetoplumbite-type crystal structure, wherein
 x1, x2, y, and m satisfy the following Equations (6), (7), (8) and (9) when composition of the ferrite sintered magnet is represented by R 1-x1-x2 Ca x1 Sr x2 Fe m-y Co y , where R denotes at least one kind of element selected from rare earth elements including Y:
   0.2≤ x 1≤0.5  (6)
 
   0≤ x 2≤0.1  (7)
 
   0.2≤ y ≤0.4  (8)
 
   6.5≤ m ≤9.5  (9),
 
 
 a content of B is from 0.2% to 0.4% by mass or less in terms of B 2 O 3 , and a content of Si is less than 0.3% by mass when Si is converted into SiO 2 , and 
 wherein a coercive force of the ferrite sintered magnet at 20° C. is 652 Oe or more. 
 
     
     
       2. The ferrite sintered magnet according to  claim 1 , wherein the following Equations (4) and (5) are satisfied:
   0.2≤ x 1 +x 2<0.55  (4)
 
   7.5< m≤ 9.5  (5).
 
 
     
     
       3. A motor comprising the ferrite sintered magnet according to  claim 1 . 
     
     
       4. A generator comprising the ferrite sintered magnet according to  claim 1 .